Telegraphy



M.. BRUCE, JR.

TELEGRAPHY. v l 'Alfrglfcfmon FILED MAY|3.1916. j 14,3'69,-2f18. Patented Feb. 22,1921.

WILLIAM M. BRUCE, JR., or SPRINGFIELD.' omo.v

y'InLEGRAPIIY.

specification of Lettersratent. f Patentdpeb.' 22, 1921,.

Application led May 13, 1916i.. Serial No.,k 97,425.

To allwhom t may concern.' l

Beit known that I, WILLIAM M. Brucia, Jr., a citizenv of thel United States, residing at Springfield7 in the county of Clark and State of Ohio, have invented certain newk and useful Improvements 1n 'Ielegraphy7 ofy which the following is a specification.

My invention relates to improvements in telegraphy and especially to-systems operating upon lines where the resistance and capacity Vhave a tendency to startthe signals. In sending Morse code over ordinary land line circuits it has been necessary to have repeaters owing to the polarization of line1 and instruments,"cli1e toa larger charge of one polarity in makinga long character or when spacing, even when lreversals are used. Attempts vhave been made to overcome this by the-use oftransformers byv whichmo- Vmentary `impulses are applied to the line,

but in such cases there being no current from the transmitting station tohold the receivl ing `relay in its operated position, this relay would be subject to outside disturbancesuch as power or other circuits in proximityV to otherlines, also the breaking of the primary circuit in the transformer induces a `circuit in the. opposite direction which would effect the receiving relay andlresult in false sig-- nals.

In my vimproved system .I'employ momentaryimpulses of substantially equal dura tion at the beginning and end 'of the characters and impress these impulses uponv the primary of atransformer with the second,- lary ofthe transformer connectedfto the line and I further provide means vfor .breaking the secondary" at the same time the primary is broken and also apply a holding 4current of'the same polarity asl theipreceding induced current Vin the secondary andthe line so thatV the receiving Arelay will be positively held in its operated position and not be d lsturbed Vby outside impulses or byl the. 1nduced current of opposite. polarity induced by the breaking of the primary. ,Y Y

lIn my improved system I employ momentary impulses of substantially equal duration atthe beginning and end of characters which are of unequal'duration and impart these. impulses to a primary.- of transformer thel secondary of the transformer being connected .to Y the line .and further provide means for applying a holdingcurrent cf 'the samepolarity as the inducedjcurrent inl the secondary or line so that the receiving; relay will remain its operated position and not be disturbedby outside influence. y vThe accompanying drawing is a diagram of circuits. andapparatus wlnchI have' em ployed and which are illustrativeof the invention yherein described vand claimed. ...In

these drawings Arepresents an ordinary telegraphkey Vwhichris connected'in circuity with a relay A whose armature moves between contacts A? and' A3 which are con# Vnected-.to the opposite poles Vof'ajbattery B.

VThe varmature A? ofv this relay .is connected l which relay is connected'bywiretothe `to what I term the sending relay-bby wire Y armature c of a cuteoff vrrelay c, the armature c of the cut-'off relay c being arranged to move between contacts c2 and c3 which .are ,also connected to. opposite Vpoles of the-bartf Y tery B by .wires 3 and 4.V Eachof the relays b and c arerpolarized relays and adapted to.

be moved in: one position bya negative impulse and in the otherposition byia posi'- tive impulse from the battery B. The armas` turebuof the relay b: also operates between contacts Zand b3 which are connected to the oppositel poles of the` battery B bywiresl land 6,;the armature bbeing also'connected by wire 7 to the primary windingrfof ,a'transf former T and thence'bywire 8 tothe armature c of the cut-'o i'relay c and to theopl posite pole of the battery B by wire 4.`

In the normal position shown it willbe Y noticed that the armatures of thesending and cut-off relays are .both resting .against contacts whichY are -connected -to'the negative pole of the-battery and no current isflowing. 'Ifthe lkeyfiiL vshouldV be; operated; the:

relay A. wouldbev operated. and move its i armatureAffrom thenegative 'Contact A?" .to thepositivecontact A2 of the battery B.

Thiswouldgsend a positive impulse tothe sending relay Vfand would causethe armatureV b ofthe sending. relay to move to the positive contact Z92- and sendA af' positive impulse off current vthrough the 'primary' ofV the transformer, the cut-off relay c'being con-y necteid inparallel'with thegprimary Winding I I ofthe transformer wouldl :be operated by the same impulse but it is so connected o-r constructed'that itis operated at al predetermined time after lthe sending relay opcrates. I have shown" inductive `resistance r in` circuit4 with vthis relay for the y purpose. When yrelay; c is operated itcutsoif` the current to thesen'dingirelay, also the current j :tothe transformer andto itself and sincef-it'sj 5; i

armature is moved to the contactV c2 connected to the opposite pole of the batteryall of the contacts will be with the positive pole of the battery and no current will flow. v As soon as the key A is released it breaks the circuit for the relay A and its armature A* will return to normal position which will cause the armatures of the relays-Z) and c to return to their normalk positions with the resultthata negative impulse will be, sent from the battery B to the primary of the transformer andthe cut-off relay lrespec- -v tively,-which negative impulse will be cut off after a predetermined time by the relay c in-the manner heretofore described and thus momentary impulses of opposite polarity will be impressed upon the primary I winding of the transformer ateach downward and upward movement-of, the key to register the beginning and end of a'character vsuch as a dot or dash.

' Thesecondary winding of the transformer is'connected to the line under the` usual duplexconditions by wire 9 and for each momentary impulse, negative or positive, a corresponding impulse is sent intothe line and will yoperate the distant polarized relay on the vmain line in theI usual manner.

Inasmuch, however, as these'impulses that operate the receiving relay are momentary,

-the relay'might not Vbe held in its operated 'also connected to the opposite poles ofthe battery B by wires V11 and 12, the poles, however, being reversed on these contacts from those onthe contacts b2 and b3 of the arma- Y ture so that when the mainarmature of thence through the armature c of the cut- Y the relay in its operated position.`

relay b isrestingon anegative contact the extension Zi* Vwilll be rresting on a positive contact and as the secondary winding is also connected by wire 8 to the armature cl of the cut-off` relay c, which will 'be' normally on a contact ofopposite polarity, a circuit will be formed from earth through the eX- tension armature through the battery and off relay and the secondary winding and line to yearth at the' distant station thus holding Vhen the relays assume their opposite positions theppposite pole ofl thev battery will' be 4grounded by the extension b4 of the armaturel-and an impulse ofv opposite polarity will be impressed on vthe lineand the distant relay will remain inits operated position'k 'battery on the line. erated it transmits a sending impulse, this until-the relays b and c are again operated so that after each ,momentary impulse is transmitted to the line through the transformer, there will be a continuous current of the same polarity as the last induced impulse impressed upon the line to hold the distant relay in its operated position.

It will be observed that the circuit from ground at the sending station to ground at the receiving station, through the secondary of the transformer and the line, passes through the wire 8 connecting the secondary to the armature c and thence (in the position shown in the drawing) through contact c3, wire 4, battery B, wire 5, wire 12,-contact b, armature extension L4, wire vl() toground at g. It will thus be seen that when-cut-off relay4 e operates to cut-oif the impulse to the primary of the transformer' it also breaks the 4circuit for the secondary and no' -discharge in the line or in the currentof'opposite polarity'due to the breaking 'of the current inthe primary can occur to affect the distant receiving relay. This results in the distant receiving polarized' relay being operated by impulses of high potential current and of momentary duration by means 'of Ythe transformer, vwhile the distant vreceiving relay is held in its position by a' con-V stant current supply of low potenti-'al which to the extent that the high-potenial current necessary to operate the distant receiving polarized relay would. f

In the normal condition as shown in the drawings the line circuit to the distant-re ceiving relay passes from ground g 'at'the sending station through. the shunt s, line does not polarize the instruments and'lin'es 10, extension b, contact'b, wire 12, wire 5 to battery B, wire 4e, contact c3, armature c', wire 8, secondary of the transformer Vand line 9v with the holding'- currentV from the When the key 'is opcircuitv will be broken Vat the contacty be andthe ground applied through contact'b, wire 11', wire 46, wire 4,-, contact c3, armature o', wire 8, secondary of the ,transformer and At the same time this change is made from contacto(i to contact tithe relay e will be operated, opening the shunt around ground circuit and compensating for the absence of the resistance of the battery inith'is iio line 9, the battery'not being included in this circuit.

i the resistance r thus includingv it in the circuit during the momentary lperiod before i the cut-off relay operates to move its armature from contact c3 to. 02 by which thebattery will againbe included in the circuit andthe current forthe relay e cut off and 'the shunt around the resistancev r* closed.

ThisV maintains constant Vconditions Ato reworking.

Having thus described vmyv invention, I claim:

l. In a system of telegraphy, the method of transmitting characters of unequal duration such as dots and dashes which consists y in supplying from a battery to the primary of a transformer current impulses of opposite polarity and of substantially Y equal duration at the beginning and end of each character and Vimpressing the induced current impulses from the secondary of the transformer to a conductor to operate a distant translating device on said conductor byl said induced or transformed current impulses substantially as specified. 1

2. The method of transmitting signals of unequal duration, such as dots and dashes, which consists in impressing impulses of opposite polarity upon one winding of a transformer, inducing corresponding impulses in the other winding and impressing these upon a line, automatically cutting off these impulses so as to make them equal or of substantially equal duration and followbefore the succeeding impulsesof opposite polarity are induced in the transformer. e

' 4. In a system of telegraphy in which impulses of opposite polarity arei impressed upon one winding of a transformer7 inducing corresponding impulses on the other winding and impressing these upon a line,

Vwhich impulses are automatically' cutoff so asV to make them of substantially equal duration and followed by a holding current n of the same polarity as the induced current, means for breaking the circuit ofthe induced current in one winding of the trans-V former at the *Same time -that the impulse impressed uponl the other winding is cut off.

5. In a system of telegraphy in which impulses of opposite polarity and of substantially equal duration arefimpressed from-a battery upon one winding of a transformer,

ing current of thesame polarity as the induced current and whichholdmg current inducing corresponding impulses Y in the Y other winding and impressing these upona .line7 which impulses are followed by alioldf n is cut off before the succeeding impulse-of oppositev polarity is induced inthe line,

- means' substantially kas described for auto? matically introducing in the circuiti resist- `ance equal to the resistance of the battery during theV time the holding current Vis mo-y mentarily cut off theline.A

In testimony whereof I have hereunto setA my` hand this 3rd day of May, 1916. j

` WILLIAM-M. BRUCE,JR. Witness: Y

CHAS. I. WELCH. 

